One conventional side panel assembly line of the type described above is known from Japanese laid-open patent publication No. 62-263876. The technology disclosed in the above publication is concerned with an automobile side panel assembly line having a setting station, a welding station, and a next working station which are arranged successively in a series in the order named, the automobile side panel assembly line comprising a first setting carriage reciprocally movable between the setting station and the welding station, and a second setting carriage reciprocally movable between the welding station and the next working station, the arrangement being such that a side panel can be transferred between a clamp member disposed in the welding station for holding the side panel and each of the setting carriages.
According to the technology disclosed in the above publication, constituent members of a side panel are set on the first setting carriage in the setting station, and the first setting carriage is moved to the welding station. In the welding station, the constituent members of the side panel are temporarily welded, and then transferred from the first setting carriage to the clamp member in the welding station. While the constituent members of the side panel are being held by the clamp member, the constituent members are additionally welded. During the additional welding process, the first setting carriage is moved back to the setting station where constituent members of a next side panel are set on the first setting carriage.
When the additional welding process is finished in the welding station, the second setting carriage is moved back to the welding station, and the constituent members of the side panel are transferred from the clamp member to the second setting carriage. Then, the second setting carriage is moved to the next working station.
While the second setting carriage is being moved to the next working station, the first setting carriage is moved to the welding station where the constituent members of the side panel are temporarily welded.
According to the technology disclosed in the above publication, therefore, the welding process in the welding station and the process of setting the constituent members of the side panel in the setting station are carried out parallel to each other. Consequently, side panels can be assembled sequentially for increased productivity.
However, the technology disclosed in the above publication is time-consuming and remains to be improved because, in the welding station, the constituent members of the side panel are transferred from the first setting carriage to the clamp member, and after the welding process is finished, the constituent members are transferred from the clamp member to the second setting carriage.